Skip to main content
. Author manuscript; available in PMC: 2014 Nov 6.
Published in final edited form as: J Neural Eng. 2012 Nov 27;9(6):065002. doi: 10.1088/1741-2560/9/6/065002

Figure 2.

Figure 2

(A) Schematic diagram illustrating the general concept of encapsulated cell-based therapies. Cells which secrete therapeutic products such as neurotrophins (NTs) are encapsulated in a biocompatible, semi-permeable membrane which allows for outward diffusion of the therapeutics as well as waste products, and inward diffusion of oxygen and nutrients for survival of the transplanted cells. The membrane also provides an immunoprotective barrier to the transplanted cells. The second panel in (A) shows an example of cells encapsulated in an alginate membrane; these are clusters of BDNF-expressing Schwann cells. (B) Photomicrographs showing spiral ganglion neurons (SGNs) (arrows) in the deaf guinea pig cochlea after implantation of BDNF-expressing Schwann cells (treated) or empty control capsules (untreated). Cell-based NT delivery using modified Schwann cells for a two and four week treatment period resulted in enhanced SGN survival in the treated cochlea compared to the control (modified from [52]). (C) Cell-based NT delivery using choroid plexus cells (cells that naturally produce and release neurotrophins), alone (NT) or in combination with chronic electrical stimulation (ES+NT) from cochlear implant, also enhanced SGN survival over a long-term (6 months) treatment period in the deafened cat (modified from [45]).